diff options
Diffstat (limited to 'ares/ares_query.c')
-rw-r--r-- | ares/ares_query.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/ares/ares_query.c b/ares/ares_query.c new file mode 100644 index 000000000..5801ef94f --- /dev/null +++ b/ares/ares_query.c @@ -0,0 +1,112 @@ +/* Copyright 1998 by the Massachusetts Institute of Technology. + * + * Permission to use, copy, modify, and distribute this + * software and its documentation for any purpose and without + * fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting + * documentation, and that the name of M.I.T. not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" + * without express or implied warranty. + */ + +static const char rcsid[] = "$Id$"; + +#include <sys/types.h> + +#ifdef WIN32 +#include "nameser.h" +#else +#include <netinet/in.h> +#include <arpa/nameser.h> +#endif + +#include <stdlib.h> +#include "ares.h" +#include "ares_dns.h" +#include "ares_private.h" + +struct qquery { + ares_callback callback; + void *arg; +}; + +static void qcallback(void *arg, int status, unsigned char *abuf, int alen); + +void ares_query(ares_channel channel, const char *name, int dnsclass, + int type, ares_callback callback, void *arg) +{ + struct qquery *qquery; + unsigned char *qbuf; + int qlen, rd, status; + + /* Compose the query. */ + rd = !(channel->flags & ARES_FLAG_NORECURSE); + status = ares_mkquery(name, dnsclass, type, channel->next_id, rd, &qbuf, + &qlen); + channel->next_id++; + if (status != ARES_SUCCESS) + { + callback(arg, status, NULL, 0); + return; + } + + /* Allocate and fill in the query structure. */ + qquery = malloc(sizeof(struct qquery)); + if (!qquery) + { + ares_free_string(qbuf); + callback(arg, ARES_ENOMEM, NULL, 0); + return; + } + qquery->callback = callback; + qquery->arg = arg; + + /* Send it off. qcallback will be called when we get an answer. */ + ares_send(channel, qbuf, qlen, qcallback, qquery); + ares_free_string(qbuf); +} + +static void qcallback(void *arg, int status, unsigned char *abuf, int alen) +{ + struct qquery *qquery = (struct qquery *) arg; + unsigned int ancount; + int rcode; + + if (status != ARES_SUCCESS) + qquery->callback(qquery->arg, status, abuf, alen); + else + { + /* Pull the response code and answer count from the packet. */ + rcode = DNS_HEADER_RCODE(abuf); + ancount = DNS_HEADER_ANCOUNT(abuf); + + /* Convert errors. */ + switch (rcode) + { + case NOERROR: + status = (ancount > 0) ? ARES_SUCCESS : ARES_ENODATA; + break; + case FORMERR: + status = ARES_EFORMERR; + break; + case SERVFAIL: + status = ARES_ESERVFAIL; + break; + case NXDOMAIN: + status = ARES_ENOTFOUND; + break; + case NOTIMP: + status = ARES_ENOTIMP; + break; + case REFUSED: + status = ARES_EREFUSED; + break; + } + qquery->callback(qquery->arg, status, abuf, alen); + } + free(qquery); +} |